Intestinal obstruction Bowel obstruction - PowerPoint Presentation

Slide1

Intestinal obstruction

Slide2

Bowel obstruction

(or

intestinal obstruction

) is a mechanical or functional obstruction of the intestines, preventing the normal transit of the products of digestion. It can occur at any level distal to the stomach and it is a surgical

emergency

. The condition is often treated conservatively over a period of 2-5 days with the patient's progress regularly monitored by an assigned physician. It’s a common cause of acute abdominal pain and represents 5%-20% of acute surgical admission.

Slide3

Epidemiology

1% of all hospitalization

3% of emergency surgical

admissions

More frequent in female patients because of gynecological-obstetric and pelvic surgical operations are important etiologies for post operative adhesions

Adhesion is the most common cause of intestinal obstruction

80% of bowel obstruction due to small bowel obstruction and the most common causes are adhesion—hernia---neoplasm while 20% due to colon obstruction and the most common cause is CR-cancer 60-70% while 30% are

diverticular

disease and

volvulus

Mortality rate range between 3% for simple bowel obstruction to 30% when there is strangulation or perforation

Recurrent rate vary according to method of treatment if conservative 12% while the operation treatment recurrent rate 8-32%

Slide4

The Questions that should be answered in patient with IO:

-Is this bowel obstruction or

ileus

?

-Is this a small or large bowel obstruction?

-Is this proximal or distal obstruction?

-What is the cause of this obstruction?

-Is this a complex or simple obstruction?

-How should we start investigation the patient?

-What is the immediate/ intermediate treatment plan?

-What are the indications for surgery?

-

Slide5

Types

On the basis of presence or absence of bowel activity

Dyanamic

A mechanical blockage acting as a barrier to the progression of gut contents

.

Adynamic

:

is a paralytic or functional variety of obstruction

Slide6

Classification of intestinal obstruction

1-Small bowel obstruction &large bowel obstruction.

2-Mechanical obstruction & functional obstruction.

3-Simple obstruction & complicated obstruction.

4-Partial obstruction& complete obstruction .

5-Acute obstruction

-Sub acute obstruction

-Acute on chronic obstruction .

-Chronic obstruction.

6-Congenital &acquired

Slide7

8L of isotonic fluid received by the small intestines (saliva, stomach, duodenum, pancreas and

hepatobiliary

)

7L absorbed

2L enter the large intestine and 200 ml excreted in the faeces

Air in the bowel results from swallowed air ( O

2

& N

2

) and bacterial fermentation in the colon ( H

2

, Methane & CO

2), 600 ml of flatus is releasedEnteric bacteria consist of coliforms, anaerobes and strep.faecalis.Normal intestinal mucosa has a significant immune roleDistension results from gas and/ or fluid and can exert hydrostatic pressure.In case of BO Bacterial overgrowth can be rapidIf mucosal barrier is breached it may result in translocation of bacteria and toxins resulting in bactaeremia, septaecemia and toxaemia.

Patho

-physiology I

Slide8

Patho-physiology II

Obstruction results in:

Initial overcoming of the obstruction by increased

paristalsis

Increased

intraluminal

pressure by fluid and gas

Vomiting

sequestration of fluid into the lumen from the surrounding circulation

Lymphatic and venous congestion resulting in oedematous tissues

Factors 3,4,5 result in

hypovolaemia

and electrolyte imbalanceFurther: localised anoxia, mucosal depletion necrosis and perforation and peritonitis.Bacterial over growth with translocation of bacteria and it’s toxins causing bacteraemia and septicaemia.

Slide9

Causes of small IO:-

Extraluminal

Mural

Luminal

Adhesions

Hernia

Volvulus

Neoplasms

Crohns

TB

Intussusception

Congenital

F. Body

Bezoars

Gall stone

Food Particles

Ascaris

Slide10

Etiology

Mechanical bowel obstruction:

Small bowel obstruction:

Adhesion 60%

Hernia 20%

Neoplasm 5%

Volvulus

5%.

Others: IBD-GALL STONE-FOREIGN BODY-INTUSSUSCEPTION.

Large bowel obstruction :

Cancer 60%.

Diverticular

disease 15%.Volvulus 15%.Others: hernia –fecal impaction-inflammatory.

Slide11

Features of obstructions

In high small bowel obstruction ,vomiting occurs early and is profuse with rapid dehydration .Distension is minimal with little evidence of fluid levels on abdominal radiography.

In low small bowel obstruction, pain is predominant with a central distention .Vomiting is delayed. Multiple central fluid level are seen in radiography.

In large bowel obstruction, distension is early and pronounced .Pain is mild and vomiting and dehydration are late .The proximal colon and

caecum

are distended are distended on abdominal radiography .

Slide12

Cardinal clinical features of acute obstruction :

Abdominal pain

Distension

Vomiting

Absolute constipation .

Slide13

Abdominal pain

Most patients who have small –bowel obstruction experience

crampy

abdominal pain that comes in wave .The pain is around the umbilicus.

Slide14

Vomiting

Small bowel obstruction usually cause vomiting The vomit is green if the obstruction is in the upper small intestine and brown if it is in the lower small intestine.

Slide15

Constipation

Constipation and inability to pass gas are signs of bowel obstruction .However ,when the bowel partially blocked a person may have stool leak and pass gas. Patient with a complete obstruction may have a bowel movement if there is stool below the obstruction.

Slide16

Distension

With the blockage of the lower small intestine ,the

epigastric

area may be

distinded

or bloated.

Slide17

Clinical features of strangulation

Constant pain

Tenderness with rigidity

Shock

Discoloration

Constitutional symptom

Slide18

Slide19

Clinical Findings

Examination

Others

Systemic examination

If deemed necessary.

CNS

Vascular

Gynaecological

musculoskeletal

Abdominal

Abdominal distension and it’s pattern

Hernial orifices

Visible peristalsis

Cecal distension

Tenderness, guarding and rebound

Organomegaly

Bowel sounds

High pitched

Absent

Rectal examination

General

Vital signs:

P, BP, RR, T, Sat

dehydration

Anaemia, jaundice, LN

Assessment of vomitus if possible

Full lung and heart examination

Slide20

Initial Management in the ER

Resuscitate:

Air way (O

2

60-100%)

IVF : Crystalloids at least 120 ml/h. (determined by estimated fluid loss and cardiac function).

NPO.

Decompress with

Naso

-gastric tube and secure in position

Insert a urinary catheter (hourly urinary measurements) and start a fluid input / output chart

Intravenous antibiotics (no clear evidence)

If concerns exist about fluid overloading a central line should be insertedFollow-up lab results and correction of electrolyte imbalance“Never let the sun set or rise on an obstructed bowel ”

Slide21

How to initially investigate your patient

Lab:

CBC (

leukocytosis

, anaemia,

hematocrit

, platelets)

Clotting profile

Arterial blood gasses

U&

Crt

, Na, K, Amylase, LFT and glucose, LDH

Group and save (x-match if needed) Optional (ESR, CRP, Hepatitis profileRadilogical:Plain x-raysUSS ( free fluid, masses, mucosal folds, pattern of peristalsis, Doppler of mesenteric vasculature, solid organs)CT, MRI, Contrast studies……ECG and other investigations for co-morbid factors

Slide22

Diagnostic in 50 %

CXR

: superior to erect

abd

X ray for

pneumo

peritoneum

Abdo

X ray

: Changes appear in

3-5

hrs

if complete obstruction and take days if incomplete obstructionHigh grade SBO : > 3.6 cm diameter of loops ; 2.5 times more in number ; air fluid levels > 2 ; wider than 2.5 cm and differing in height >2 cm String of beads sign : small bubbles of gas trapped in rows between valvulae conniventes . Diagnostic of SBO (sometimes also in IBD and Ileus)Coffee bean sign: closed loop obstr where the arms of the loop dilated with gas separated by thick intestinal

wall

Pseudo tumor sign

: closed loop fill with fluid looks like soft tissue mass

XRAY

Slide23

SBO

Slide24

Fluid levels with gas above; ‘

stepladder pattern’.

Ileal obstruction by adhesions; patient erect.

 Supine radiograph from a patient with complete small bowel obstruction shows

distended small bowel loops

in the central abdomen with

prominent valvulae conniventes

(small white arrow)

 

Figure 3.

Lateral decubitus view of the abdomen, showing air-fluid levels consistent with intestinal obstruction

(arrows).

Slide25

Slide26

The Difference between small and large bowel obstruction

Small Bowel

Large bowel

Central ( diameter 3 cm max)

Vulvulae

coniventae

Ileum: may appear tubeless

Peripheral ( diameter 6 cm max)

Presence of

haustration

Slide27

Coffee bean sign

Slide28

Slide29

Slide30

LARGEBOWEL

SMALL BOWEL

Haustra

present

Absent

Number of loops

Few

Many

Valvulae

conniventes

absent

Present in jejunumDistribution of loopsPeripheral centralRadius of curvature of loopsLarge SmallDiameter5 cm3-5 cmSolid feces +-

Slide31

Water soluble contrast gets diluted

Poor mucosal detail

No therapeutic effect in SBO

Follow through

:

500 ml

of

42 %

barium ,

fluroscopic

radiographs at 15-30 min interval till

ileo

cecal valve. When barium reaches cecum put a rectal tube and insufflate air to distend the rt colon and distal iluemEnteroclysis: duodenal intubation , 30-40% barium infusion at 60-90 ml /minDouble contrast enteroclysis: followed by infusion of air / methyl cellulose BARIUM

Slide32

Role of barium

gastrografin

studies

As: follow through, enema

Limited use in the acute setting

Gastrografin

is used in acute abdomen but is diluted

Useful in recurrent and chronic obstruction

May able to define the level and mural causes.

Can be used to distinguish

adynamic

and mechanical obstruction

Barium should not be used in a patient with peritonitis

Slide33

When CT not available

Operator dependent modality

Obstruction

: lumen

> 3 cm

; length

> 10 cm

; distal

seg

shows to and fro

or whirling motion

( differentiates from ileus )

Cause can be detectedSeverity : free fluid + ; aperistalsis ; bowel wall thickening > 3 mm ( sugg infarction )USG

Slide34

Role of CT

Used with iv contrast, oral and rectal contrast (triple contrast).

Able to demonstrate abnormality in the bowel wall, mesentery, mesenteric vessels and peritoneum.

It can

define:

the level of obstruction

The degree of obstruction

The cause: volvulus, hernia, luminal and mural causes

The degree of

ischaemia

Free fluid and gas

Ensure: patient vitally stable with no renal failure and no previous

alergy to iodineFigure: Axial computed tomography scan showing dilated, contrast-filled loops of bowel on the patient’s left (yellow arrows), with decompressed distal small bowel on the patient’s right (red arrows). The cause of obstruction, an incarcerated umbilical hernia, can also be seen (green arrow), with proximally dilated bowel entering the hernia and decompressed bowel exiting the hernia.Source: Jackson, PG. & Raiji M., Evaluation and Management of Intestinal Obstruction, January 2011, American Academy of Family Physicians (AAFP), 83: 2 (160-164)

Slide35

Slide36

Can detect extra luminal

patho

and detailed info about the small bowel wall.

And does not use

ionised

radiation

MR ENTEROCYLSIS

Slide37

Initial Management in the ER

Resuscitate:

Air way (O

2

60-100%)

Insert 2 lines if necessary

IVF : Crytloids at least 120 ml/h. (determined by estimated fluid loss and cardiac function). Add K

+

at 1mmmol/kg

Draw blood for lab investigations

Inform a senior member in the team.

NPO.

Decompress with Naso-gastric tube and secure in positionInsert a urinary catheter (hourly urinary measurements) and start a fluid input / output chartIntravenous antibiotics (no clear evidence)If concerns exist about fluid overloading a central line should be insertedFollow-up lab results and correction of electrolyte imbalanceThe patient should be nursed in intermediate careRectal tubes should only be used in Sigmoid volvulus.

Slide38

INDICATIONS FOR SURGERY

Absolute

Generalised peritonitis

Localised peritonitis

Visceral perforation

Irreducible hernia

Relative

Palpable mass lesion

'Virgin' abdomen

Failure to improve

Trial of conservatism

Incomplete obstruction

Previous surgeryAdvanced malignancyDiagnostic doubt - possible ileusSource: http: Surgical Tutor.co.uk

Slide39

Ileus

Associated with the following conditions:

Postoperative and bowel resection

Intraperitoneal infection or inflammation

Ischemia

Extra-abdominal: Chest infection, Myocardia infarction

Endocrine: hypothyroidism, diabetes

Spinal and pelvic fractures

Retro-peritoneal haematoma

Metabolic abnormalities:

Hypokalaemia

Hyponatremia

UraemiaHypomagnesemiaBed riddenDrug induced: morphine, tricyclic antidepressants

Slide40

Acute Mesenteric Occlusion

Acute ischemic of mesenteric vessel.

Commonly SMA

Causes: AF, mural thrombosis,

atheromatous

plaque from aortic aneurysm and

valave

vegetation from endocarditis

Features: -Sudden onset of severe

abd

. pain in

pt

with AF and atherosclerosis -Persistent vomiting and defecation then passage of altered blood -Hypovolumic shock Investigations: - Neutrophil leukocytosis - Abd Xray: Absence of gas in thickened small intestinesTreatment: - Anti-coagulant - Embolectomy - Revascularization - Colectomy

Slide41

PSEUDO-OBSTRUCTION

Obstruction usually colon- occur in the absence of mechanical cause or acute intra-abdominal disease.

Associated with a variety of syndromes in which there is underlying neuropathy and/or a range of other factors

IDIOPATHIC

SEPTICAEMIA

Metabolic

Retroperitoneal irritation

Severe trauma

at lumbar

area

Drugs

ShockSecondary GI involvement

Slide42

Upright abdominal X-ray demonstrating a small bowel obstruction. Note multiple air fluid levels

.

Slide43

Upright abdominal X-ray of a patient with a large bowel obstruction showing multiple air fluid levels and dilated loops of bowel

.

Slide44

Hernia

Slide45

Other causes of small

io

.

IBD

Gall stone Ileus

Intussusception

Slide46

Sigmoid Volvulus

Colonic Obstruction

Slide47

Ileus